JPS6020187B2 - Container sealing method and device - Google Patents

Abstract

Apparatus is disclosed for use with a conventional bottom closure folding machine for ultrasonically sealing folded carton bottom closures having at least two differing thicknesses or laminates comprising, in part, a unique sealing horn and multi-surface mandrel pad arrangement which makes possible the ultrasonic sealing of a laminated bottom closure of varying thicknesses for a container composed of thermoplastic double coated foldable material such as, for example, a polyethylene double coated paperboard carton. The sealing horn comprises a substantially conventional body portion surmounted by a face having a recessed portion and a raised portion for forcibly engaging the folded carton bottom closure and forming an ultrasonic seal at predetermined critical areas of the bottom closure. The multi-surface mandrel pad has a multiplicity of surfaces which lie in at least two distinct planes and which are shaped to receive and engage sections of tabs and panels of the folded carton bottom closure so that when the sealing horn and multisurface mandrel pad are forcibly urged together, the force exerted on the folded carton bottom closure over the area of contact between the face portion of the sealing horn and the surface of the folded carton bottom closure is substantially uniform. The multi-surface mandrel pad, through its multiplicity of surfaces, receives and engages sections of tabs and panels of the infolded surface of the folded carton bottom closure during sealing thereby preventing excessive vibration of those portions of the carton bottom closure which are not in forcible engagement with the raised portion of the sealing horn face during sealing thereby avoiding unwanted "burn through".

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for sealing containers, in particular foldable materials double coated with thermoplastics, such as polyethylene for the packaging of milk and other dairy products. Concerning an ultrasonic liquid-tight seal of the bottom of a heavily coated cardboard container.

Over the past three years, the packaging industry has experienced revolutionary changes in technology.

In the milk packaging industry, where this invention has the greatest application, containers have undergone a transformation from retrievable glass dust to waxed cardboard to thermoplastic coated cardboard containers. The material for the latter type of carton mentioned above is cut by the paper manufacturer, creased for folding, and folded into a tube shape with liquid-tight joints along the side greens. put. The carton material is then fed into a folded flat shape to the milk filler. Usually, in the final packaging process, the carton material is expanded into its tubular shape, a liquid-tight lid is formed at the bottom of the carton, the carton is filled, and the top of the carton is then closed, e.g. It is necessary to seal with a liquid-tight seal such as an outlet seal.
The prior art most relevant to the present invention relates to devices for forming carton bottom lids with liquid-tight seals.

In the case of cardboard containers double-coated with thermoplastic, the bottom lid panels and tabs, whose shape is determined by the contours of the carton material and the shape of the folds, are coated with said double-coat of thermoplastic. In order to activate
Fin radiant heat, usually gas or electricity, and high-temperature hot air are applied, and then the bottom of the carton is bent straight into its sealed position to bond the activated thermoplastic into a rigid Q-flat state. It is placed under pressure in that position until cooled to form a liquid-tight seal between the bottom panel of the carton and the tap. Conventionally known folding for this top and bottom)
An example of a encapsulation technology is Engleston (Engestone).
ton et al., U.S. Pat. No. 3,102,335, and Seiple, U.S. Pat. No. 3,120,3.
It is disclosed in the specification of No. 33. Prior art sealing techniques using gas or electric heating and high-temperature hot air have long been considered difficult to implement; This is because it is difficult to uniformly distribute heat and keep the activity of the thermoplastic plastic constant during the stopping process.

Furthermore, the packaging processing areas of such processing plants are often heated to an undesirable degree during the sealing process, presenting a constant fire hazard. In order to eliminate the above-mentioned defects, an ultrasonic sealing technique has been developed and has achieved some success. For example, it is possible to seal the top of a carton using ultrasonic waves, thereby eliminating the need for gas or electric radiation and hot air in all packaging steps following the closure of the carton bottom. Until now, there were clues to a technical solution.
An example of this ultrasonic top closure technique is Obeda (Ob
No. 3,486,731. There has been some research and experimentation regarding the use of ultrasonic techniques to bond layers of different thickness using textured surfaces in ultrasonic sealing devices. An example of this research and development is proprietary patent No. 2,165.62'
This is described. However, these techniques have hitherto been insufficient for the purpose of sealing the bottom lid of a carton. The reason for this is the difficulty of sealing a tubular container, including the problem of uncontrollable "burning", especially when the container closure consists of several layers of laminated surfaces with different thicknesses. This is because ultrasonic sealing does not cover sealing parts with complex shapes and cross sections. Like this,
This technique solves problems, including the uncontrollable "burn" problem mentioned above, while simultaneously providing a paperboard container double-coated with thermoplastic, such as a double-coated polyethylene cardboard carton. When sealing the bottom lid of a carton, it is desirable to completely eliminate the need for gas or electric radiation and high-temperature hot air. This is particularly desirable in the packaging of liquids such as other dairy products. A conventional bottom lid folding machine for sealing the bottom lid of a cardboard container double coated with thermoplastic plastic, such as a pole paper carton double coated with polyethylene, using ultrasonic waves. The bag eye includes an ultrasonic oscillator, a sealing horn part, a multi-sided mandrel pad, and a part for pressing the sealing horn and the multi-sided mandrel pad into a forced engagement relationship. It has a drive device.

The sealing horn has a main body portion with one surface having a concave portion and a convex portion.

The convexity on the surface defines the form of the bottom lid, and the folds are formed to improve the transmission of vibrations from the ultrasonic oscillator and the sealing action horn to the sealing area of the bottom lid of the folded carton. It is desirable that a The surface of the multi-sided mandrel pad is surrounded by a series of generally vertical panels, shaped and recessed to accommodate the tabs and panels of the bottom lid of a folded carton. at least two different faces spaced apart by a distance preferably equal to an integral multiple of the thickness of the cardboard used for cardboard containers double-coated with thermoplastic plastic, the bottom lid of which is sealed; It is desirable that they be in parallel positions within each other. At least one side contains a bottom lid portion of folded cardboard having the thickness of a sheet of cardboard double-coated with thermoplastic plastic in the outermost side; engage with. At least the other surface is recessed from the outer surface by a length that is an integral multiple of the thickness of the cardboard used in the double-coated cardboard container; 2 of double coated cardboard
The surface which accommodates and engages the part of the bottom lid consisting of layers and which is recessed by N times the thickness (N is an integer) is made of N+1 of cardboard further coated with thermoplastic plastic. Each part of the bottom cover part consisting of twice the number of layers is accommodated and engaged with the bottom cover part. To form the bottom seal, the material of the carton is mounted on a multi-sided mandrel pad, the shape of the circumference of the body of the pad being approximately the same as the inside of the tubular body of the carton. The outermost surface of the mandrel pad is directed toward the bottom end of the tubular, uncollapsible carton blank to force the carton blank to assume its tubular shape.

The bottom lid is then pushed into its closed and sealed position and folded using a plow in a known manner. When the bottom lid is folded, the folded tabs and panel parts of the bottom lid are accommodated within the mandrel pad according to the shapes and layer thicknesses described above. This in combination produces a generally flat outer surface for engaging the convexity of the sealing horn surface with uniform force. After the folding process, the sealing horn is subjected to ultrasonic vibration by an ultrasonic oscillator and is directed to the mandrel pad, which is loosened by the folded carton by the bottom folding device drive device. Being pushed. This folded carton bottom lid is held between a sealing horn and a mandrel pad having multiple sides, and the bottom lid is held between the mandrel pad and the convex portion of the sealing horn surface. The section is briefly subjected to ultrasonic waves to cause the thermoplastic of the section to bond and flow together with the thermoplastic on the adjacent sides of the cardboard double coated with the thermoplastic of the section. The ultrasonic generator is then stopped and the sealing horn and multi-sided mandrel pad are forced into engagement while the bonded thermoplastic returns to a solid state and the sealing horn surface is forced into engagement. A liquid-tight seal is formed between adjacent layer sections throughout the area defined by the protrusions. Thereafter, the sealing horn and multi-sided mandrel pad are separated and the bottom sealed carton is removed from the mandrel pad. The shape of the convex part on the surface of the sealing action horn roughly matches the shape of the tab on the bottom cover of the Cartso in the folded position and the folded green part of the panel and the overlapping part. An ultrasonic carton bottom lid seal is formed at all edges and overlapping areas to ensure a leak-free bottom seal.

Sealing action Taps and panels on the bottom lid of the carton that are not sandwiched between the convex portion of the horn surface and the multi-sided mandrel pad have a damping effect resulting from their engagement with each side of the mandrel pad. Excessive oscillations (or "jumping") are prevented. The bottom seal is not uniform due to the action of the tap on the bottom lid of the folded cartoso and the recess of the mandrel pad that accommodates the various thicknesses of the panel, so that the sealing action horn and A substantially flat surface for forcible engagement extends over all of the portion of the bottom cover sandwiched between the convex portion of the sealing horn surface and the mandrel pad having multiple surfaces. This produces an approximately average engagement force.After the sealing process,
The carton is removed from the multi-sided mandrel pad, filled and finally sealed at its top opening.

In order to facilitate the removal of the carton from the mandrel pad, each profile and side wall surface of the mandrel pad is designed such that, after sealing, the sealed bottom lid and each surface of the multi-sided mandrel pad meet. Ventilation is provided to introduce air into the intervening areas to prevent vacuum suction that would otherwise occur. Thus, one of the main objects of the present invention is to produce two thermoplastic materials, such as cardboard cartons double coated with polyethylene, without the use of gas or electric fin radiation and high temperature hot air. The present invention provides a method and apparatus for sealing the bottom lid of a heavily coated cardboard container.

Another object of the present invention is to provide a conventional bottom lid folding device equipped with an ultrasonic oscillator and a driving device for ultrasonic sealing of the bottom lid of a cardboard container double coated with thermoplastic plastic. The present invention provides a sealing horn and a multi-sided mandrel butt for use with a folding device.

Another object of the present invention is to forcibly engage the recess with a portion of the bottom lid, vibrate the portion of the bottom lid of the bracket at an ultrasonic frequency, and thereby The present invention provides a sealing horn having one surface having a protrusion for forming a liquid-tight seal over an area.

Still another object of the present invention is to accommodate and engage the tab and panel of the folded bottom lid of a double-coated thermoplastic container so that the surface of the sealing horn is It forms a flat surface to engage with the convex part of the sealing horn surface with uniform force, and also prevents excessive unnecessary vibration of the tap of the bottom cover part and the part of the panel that does not engage with the convex part of the sealing horn surface. To provide a mandrel butt having multiple faces for damping.

Yet another object of the present invention is to facilitate the removal of a bottom-sealed carton from a multi-sided mandrel pad so that, after the sealing operation, the bottom lid of the carton and each surface of the mandrel pad can be easily removed. The present invention provides a mandrel pad having multi-sided venting for introducing air into the area.

The foregoing and other objects, advantages and features of the invention will become apparent from the following description of embodiments of the invention, illustrated in conjunction with the accompanying drawings.

In FIG. 1, the bottom lid folding device 2 comprises a base 4, a support portion 6, and a support mandrel 8, and is further operatively associated with a tacking and folding plow 12. It has a mandrel pad 10 having multiple faces.

The sealing horn 14 and the driving device 16 are connected to the shaping and folding plow 12 (simply shown as a block in the figure) in a manner well known in the art. Subsequently, the drive device 16 forces the sealing horn 14 into engagement with the multi-sided mandrel pad 10 that is placed into the carton after the crimping and folding process for sealing purposes. Drive to. In FIG.
and a supporting mandrel 24 and a multi-sided mandrel pad 4
0 is vertically reversed relative to the sealing horn 14, support mandrel 8, and multi-sided mandrel pad 10 (FIG. 1). It is similar to the lid folding device 2 (FIG. 1).

In the apparatus of FIGS. 1 and 2, prior to the initiation of the sealing action, the plow 12 is first moved relative to the container material placed over the mandrel pad 10 (or 40) to fold the closure panel. Fold it along the lines.

The operation of such plows and the mechanisms for producing them are well known. In these figures, the plow is shown separated from the mandrel pad after completing the patching operation so as not to interfere with the subsequent sealing action. Second
In Figures 16 to 16, common elements are given the same numbers, but in Figure 3, the sealing horn 22 is
and a sealing horn surface 30, which are arranged directly above the plurality of mandrel pads 40 in the vertical direction.

The sealing horn surface 30 has a raised portion 32 and a recessed portion 34 as shown more clearly in FIG. The multi-sided mandrel pad 40 has a body portion 42, an air passageway 44, and multiple sides shown in detail in FIG. 5 and described below. In FIG. 4, the device of the invention, which is also suitable for use with any of the types of bottom lid folding devices shown schematically in FIGS. , the well-known
The actuator 27 and the ultrasonic oscillator are arranged so that the sealing active surface 30 of the sealing horn 22 is oriented to forcefully engage the multiple surfaces of the mandrel pad 40 after the crimping and folding operation. It has a sealing action horn 22 operatively coupled to 28 . The ultrasonic oscillator 28 and the drive device 27 are connected to the control box 29
is controlled by a well-known power timing device shown as .
3 and 5, the multi-sided mandrel pad 40 is attached to walls 462, 464, 466 to accommodate the various parts of the bottom and panel when the carton bottom lid is folded.
, 468 and the wall portions 482, 4
A plurality of surfaces are provided having an outer surface 48 surrounded by 84 and 486.

The outer surfaces 46 and 48 define air grooves 47 and 49, respectively;
Air groove 47 is connected to wall portion 462 by wall segments 463 and 465.
, 466, and the air grooves 49
are walls 483, 485 and 487, respectively.
It is processed to intersect with 2,484 and 486.
The multi-sided mandrel pad 40 (FIGS. 3 and 5) is
It also has second surfaces 50 and 52.

The second surface 5, outer surfaces 46 and 48, is a distance less than, and preferably equal to, the thickness of the double coated thermoplastic cardboard material used in assembling the carton for sealing. It is recessed from the wall surface 46
2,466, 468, 482, 484 and 486. A second surface 52 is also recessed from the outer surfaces 46 and 48 a distance less than the thickness of the carton material and preferably equal to the thickness of the cardboard and is recessed from the wall surfaces 462 and 48.
It consists of a surface boxed by 64. As shown in FIG. 5, surfaces 46, 48 and second surface 52 have their outer edges connected to air passageway 44 and multi-sided mandrel pad 40.
The main body portion 42 is surrounded by a peripheral portion of the main body portion 42 . Additionally, in FIGS. 3 and 5, the multi-sided mandrel pad 40 further has third sides 60, 62, 64 and 66 which cover the thermoplastic of the carton to be sealed. It is recessed from the outer surfaces 46 and 48 a distance less than twice the thickness of the double coated carton material and preferably equal to twice the thickness of the cardboard.

Third surface 60 is located between wall 462 and walls 602, 604, and third surface 62 is located between wall 466 and wall 620. Third surface 64 is located between walls 486 and 640, and third surface 66 is enclosed between walls 482 and 660. As shown, the outer edges of the third surfaces 62, 64, and 66 are relaxed by portions of the periphery of the main body 42 of the multi-sided mandrel pad 40. Finally, the multi-sided mandrel pad 40 has fourth sides 70 and 72 which are preferably 4 mm thicker than 3 times the thickness of the thermoplastic double coated material. It is recessed from the outer surfaces 46 and 48 a distance equal to twice the thickness of the cardboard. second surfaces 50, 52 and third surfaces 60, 62, 64,
66 and fourth surfaces 70, 72 and outer surfaces 46 and 48 form a planar embossed pattern corresponding to the overlap thickness of the tab and panel of the bottom lid of a known milk carton at the pouring position. do.

The distance at which the supporting surfaces are separated is the thickness of the cardboard double coated with thermoplastic used when assembling the carton to seal it, i.e. the thermoplastic is less than the polymerization thickness of the thermoplastic coating. It is desirable that the thickness be the same as that of cardboard coated with double layers. Multi-sided mandrel pad 4
The adjacent outer surfaces 46, 48, the second surfaces 50, 52, the third surfaces 60, 62, 64 and 66, and the fourth surfaces 70, 72 of the plurality of surfaces of the carton - separated by a distance approximately equal to an integral multiple of the thickness of the paper, thereby bonding the relatively thin thermoplastic coatings of each adjacent layer in areas vibrating at ultrasonic frequencies; For example, 2 thermoplastics typically used in 1-quart (approximately 0.95 liter) milk cartons.
Heavy coated pole paper consists of approximately 0.36 sided (18 mil) thick cardboard coated on both sides with a 0.012 to 0.025 sided (0.5 to 1.0 mil) polyethylene layer. . Thus, in the case of the present invention for sealing quart-sized milk cartons of the known type,
The distance between adjacent numbers is 0.36 side (18
mil) is desirable. In particular, the 18 mil pole paper thickness and the 1 quart size milk carton.
．． As opposed to a multi-sided mandrel pad of the type disclosed herein for use in sealing cardboard containers double-coated with thermoplastic having a coating of 5 to 1.0 mils thick; The second surfaces 50, 52 are preferably recessed from the outer surfaces 46, 48 a distance equal to 18 mils, and the third surfaces 60, 62, 64, 66 are recessed from the outer surfaces 46, 48 a distance of approximately 36 mils. , the fourth surfaces 70, 72 are preferably separated from the outer surfaces 46, 48 by a distance of about 54 mils. In all cases, the adjacent numbered faces are such that the folded bottom lid tabs and panel layer thicknesses are such that the sealing horn 22 and multifaceted mandrel pad 40 are forced into engagement. As long as the entire area of the convex portion 32 of the sealing horn surface 30 is compressed when mated, they may be separated by a certain distance that is not the thickness of the cardboard of the carton.
As described in more detail below, the faces of the multifaceted mandrel pad 40 are generally flat on the outer surface of the folded bottom lid to provide a sealing action horn during the closed operation. The tabs of the layers of the folded bottom lid of the folded carton are engaged with each part of the panel so as to provide uniform forcible engagement with the convex portions of the surface 30 (FIGS. 3 and 6). Store this. Although the twills and corners of the multi-sided mandrel pad 40 can be shaped in other mirror-beveled shapes to achieve the same purpose, as shown in the figure, the twills and corners of the multi-sided mandrel pad 40 are arranged in a planar shape as shown in the figure. to facilitate installation. In FIG. 6, the sealing horn surface 3
The convex portion 32 of 0 has diagonal segments 82, 84, 8
6 and 88 and green segments 90 and 92.

Additionally, the projection 32 has side seam legs 94 and flap legs 95 extending across the sealing horn surface 30 towards the green segments 90 to 92. Segment 8 of protrusion 32 of sealing horn 30 when in position to engage multi-sided mandrel pad 40 as shown in FIG.
2, 84, 86, 88, 90, 92 and legs 94, 95 have a corresponding relationship to each wall dividing the faces of multi-sided mandrel pad 40. Specifically, when the sealing horn 22 and the multi-sided mandrel pad 40 are in a forced mating position as shown in FIG. 462
．． 466, 482, and 486. Similarly, it will be seen that the lateral seam legs 94 have a corresponding relationship with the wall 602. When in the engaged position with the mandrel pad 40, the flap legs 95 of the projection 32 are in a position corresponding to portions of the second surface 50 and fourth surfaces 70, 72. Similarly, green segments 90, 92 define the outermost edges of third surface 66 and fourth surface 70, and the outermost edges of third surface 62, 64 and fourth surface 72, respectively. It is in a position that extends across. The aforementioned positional correspondence between each segment and each leg of the protrusion 32 and between each wall and each surface of the multi-sided mandrel pad 40 ensures that the bottom lid is sealed against fluid flow. This allows the sealing action, that is, the joining action, of the tab of the folded bottom lid portion and each part of the panel by ultrasonic waves. Sealing action horn surface 3
The shape of the convex portion 32 of 0 corresponds to the specific arrangement of each surface and each wall portion of the plurality of mandrel pads 40, and the convex portion 32 of
It turns out that the shape of the mandrel pad 40 has to be changed in response to changes in the multi-sided mandrel pad 40. The outer surfaces 46, 48 of the mandrel butt 40 include both bottom lid fold lines 102, 104 with the outermost edge of the second surface 52 adjacent the surface 106 of the side seam tab 108. so that it is approximately located within the plane,
It is inserted onto a multi-sided mandrel butt 40.

The carton material 100 is made up of multiple mandrel pads 40.
is placed in the same material 100 in this way to obtain its tubular form, and through the process shown in FIGS. 8 and 9, it is folded using a well-known folding plow and closed as shown in the outline drawing in FIG. 10. To be folded into position. 5, 7 and 8, as the bottom cover of the carton blank 100 is folded and folded, the first triangular panel 110 is attached to a multi-sided mandrel which is loosened by the walls 462 and 482. It is received and engaged by said portion of pad 40.

Similarly, the triangular shaped panel 112 has walls 466 and 48.
The mandrel pad 40 is accommodated and engaged with the portion of the multi-sided mandrel pad 40 surrounded by the mandrel pad 6 . As the bottom cover 200 of the carton material 100 is bent and folded into its closed position, the panels 114, 11 are folded into a triangular shape.
6 is positioned directly above the triangular panel 110, while the panels 118 and 120 folded into a triangular shape are positioned directly above the triangular panel 112. Triangular panel 110
and 112 also form the layers of the bottom lid part 200. Main panel 1
22 and 124 also rest on triangular panels 110 and 112 when the folding process is completed. The bottom diamond 2 on the multi-sided mandrel pad 40 is loosely attached to the walls 462 and 482 as a result of overlapping the panels to form the bottom lid as described above.
00, and the thickness of the layers in the portions 466 and 486.
The portion to be loosened will be at least three layers thick.
Therefore, the portion of the multi-sided mandrel pad 40 is
It is recessed from the outer surfaces 46 and 48 a distance of at least approximately twice the thickness of the cardboard double coated thermoplastic of the container to be sealed. 5 and 7, when the bottom cover 200 of the carton blank 100 is folded into its closed position, the bottom cover above the triangular panels 110 and 112 corresponding to the side seam tabs 108 200
The portions of the overlapping flap 126 and the folding flap 125 are made of two thermoplastic plastics.
It will have a folded layer thickness equal to four times the thickness of the heavily coated cardboard container material.

Thus, each surface 70 and 72 is recessed from the outer surfaces 46 and 48 a distance less than three times the thickness of the container material. The second side 52 of the multi-sided mandrel pad 40 accommodates the portion of the side seam tab 108 that is not located above the triangular panel 110 when the carton bottom is folded. Engage with this. Similarly, the second surface 50
Triangular panels 110 and 112 in the folded position shown in the figure.
Each portion of the overlapping flap 126 and the folding flap 125 that are not located above the folding flap 125 is accommodated and engaged therewith. Triangular panels 110 and 112 and those portions of main panels 122 and 124 that are not located above side seam tabs 108 are engaged by outer surfaces 48 and 46, respectively. 1st
1, 12 and 13, after the bottom cover part 200 is bent and folded in its closed position, the sealing horn 2
2 is subjected to ultrasonic vibration by an ultrasonic oscillator 28 (FIG. 4) and is pressed by a drive device 27 into forcible engagement with the multi-sided mandrel pad 40.

During this forced engagement, the bottom lid tab and panel
It is compressed and sandwiched between a plurality of surfaces on the sealing horn surface 30 and the multi-sided mandrel pad 40. The portion of the bottom cover sandwiched between the convex portion 32 of the sealing horn surface 30 and the plurality of mandrel pads 40 is given ultrasonic vibration by the vibration of the sealing horn 22. Transmission of ultrasonic vibrations from the convex portion 32 of the sealing horn surface 30 is achieved by roughening the surface of the convex portion 32, thereby reducing the contact between the outer surface 204 of the bottom cover portion 200 and the convex portion 32 of the sealing horn surface 30. This can be improved by preventing slippage between the parts. The ultrasonic vibration softens or "fluidizes" the double coating of thermoplastic plastic on the portion of the bottom cover section 200 sandwiched between the convex section 32 and the plurality of mandrel pads 40, thereby sealing. Action horn 22
The continuous force acting to push the mating surface into engagement with the multi-sided mandrel pad 40 causes the mating surface thermoplastic coating to absorb heat from the mating tab and panel in the area defined by the protrusions 32. Integrally bond with the plastic coating. After a short period of time, the ultrasonic oscillator 28 is stopped to stop the vibrating action of the sealing horn 22, and the bottom cover is held vertically for a sufficient period of time in the vertical position where force is applied. The thermoplastic coating of each part of the bottom cover part 200 between the convex part 32 of the horn surface 30 and the plurality of mastoidal pads 40 is brought into a state of collapse, and a liquid-tight sealing part is formed between the joint surfaces. That is, a joint is formed. The amount of time that the sealing horn 22 must be ultrasonically vibrated during forced engagement with the multi-sided mandrel pad 40 is such that the thermoplastic double coated ball that assembles the container to be sealed is It varies depending on the thickness of the cardboard in the paper container material. The duration of this ultrasonic vibration must increase as the thickness of the cardboard of the double-coated thermoplastic cardboard carton material increases. For cartons assembled from 18 mil thick cardboard (coating thickness 0.5 to 1 mil), 0.2
It has been found that an ultrasonic vibration duration of 2 to 2 seconds is sufficient for the formation of a liquid-tight bottom seal.

All double-coated thermoplastic containers currently in use can be aged by shaking for less than 3 seconds. The time after the vibrating action of the sealing horn, in which the bottom lid must be held upright in a compressed manner, also depends on the thickness of the cardboard double coated with the thermoplastic of the carton to be sealed. It changes depending on the situation. The required holding time also increases as the thickness of the cardboard increases. 0
．． For cartons made from 18 mil thick cardboard with a 5 to 1 mil thick thermoplastic coating, a wait time of 0.2 to 2 seconds has been found to be sufficient.

11, after the ultrasonic sealing operation, the sealing horn 22 is removed from forced engagement with the multi-sided mandrel pad 40, and the bottom-sealed carton blank 100 is removed from the multi-sided mandrel pad 40. The mandrel pad 40 is removed from the mandrel pad 40, filled with contents, and then sealed with the top lid. In Figures 13 and 14, during the static action,
The forced engagement between the sealing action horn 22 and the multi-sided mandrel pad 40 forces portions of the panels and pads of the bottom cover 200 into the multiple faces of the mandrel pad 40, resulting in the closure of the bottom cover 200. The inner surface 202 of the portion 200 substantially matches the uneven shape of the plurality of surfaces of the mandrel pad 40. Bottom cover part 2
When the 00 panels and tabs are pressed into the faces of the mandrel pad 40, the outer surface 204 of the bottom cover 200 becomes generally flat, thereby preventing the engagement of the protrusions 32 of the sealing horn surface 30. The force applied on the outer surface 204 of the bottom lid 200 is substantially uniform over the entire area of the ultrasonic seal 206, thus minimizing non-uniformity and variations in the sealing action. Or prevent this. Bottom cover part 2
Once the panels and tabs on all interior surfaces 202 of 00 are received and engaged by the surfaces of mandrel pad 40,
Undesirable "burning" and uncontrolled ultrasonic vibrations of the parts of the bottom cover part 200 that are not forcibly held between the mandrel pads 40 of the convex part 32 of the sealing horn surface 30 may cause the above-mentioned surface engagement. This is prevented by a unique vibration damping effect. 12 and 14, the bottom sealed carton blank 100 is removed within the sealed cavity created between the bottom lid 200 and the faces of the multifaceted mandrel pad 40 during the sealing action. This is facilitated by the air passage 44 and air grooves 47, 49 that introduce air into the air.

Specifically, air is introduced into the area 101 between the carton blank 100 and the support mandrel 24, and
Air passage 44 and air grooves 47, 49 shown by arrows in Figure 4
, thereby preventing vacuum suction that might otherwise occur that would prevent or make removal of the bottom-sealed carton blank 100 from the mandrel pad 40 . 15 and 16, the interior surface 202 of the bottom lid 200 (FIG. 15) after sealing includes the triangular panels 110, 112, the bottom panels 122, 124, and the side seams/tabs 108. The final positional relationship between the folding flap 125 and the folding flap 125 is shown.

The ultrasonic sealing part 206 (FIG. 16) visible on the outer surface 204 of the bottom lid part 200 extends over the entire length of the twill parts 208, 210 and extends diagonally from all four corners of the bottom lid part 200 toward the center. Extending. Additionally, the ultrasonic seal 206 extends from the edge 208 over the overlapping flap 126 to the twill 210 and from the overlapping flap 126 to the side seam tap 108 located directly below the main panel 124.
(not shown), thereby forming a liquid-tight ultrasonic seal at the bottom lid 200 of the carton blank 100. The invention is not limited to use with devices of the type shown schematically in FIGS. 1 and 2, but also with rhomboids having a sealing horn with sliding and rotational movements, and with a plurality of seals. It will be appreciated that devices having stopper horns and mandrel pads may be used without departing from the spirit and scope of the invention.

Furthermore, the preferred embodiments disclosed in the drawings represent only one example of many possible sealing horn protrusion configurations and multi-sided mandrel pad surface configurations; It will be understood that the shape and unevenness of the protrusion and the multi-sided mandrel pad are related to the specific bottom cover to be sealed, and also to the folded form of the bottom cover to be sealed. .

The apparatus disclosed as an exemplary preferred embodiment is modified to accommodate any folded bottom or top lid configuration, and has carton lids having four different thicknesses. It is also clear that this is not limited to certain departments.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view of the bottom lid folding device and the bag layer of the present invention; FIG. 3 is an enlarged perspective view showing the end faces of the sealing horn and multi-sided mandrel pad of the apparatus of the invention in the same orientation as in FIG. 2; FIG. FIG. 4 is an elevational view of the ultrasonic oscillator, driving device, sealing horn, and multi-sided mandrel pad device of the device of the present invention in the same configuration direction as FIG. 2;
Figure 6 is a plan view of a multi-sided mandrel pad of the present invention;
Figure 7 is a plan view of the sealing horn surface of the present invention; Figure 7 is a perspective view of the bottom lid of the carton after the carton material has been inserted onto the mandrel pad; Figure 8 is a view of the folding process. A perspective view of the bottom lid of the carton in the attached state; FIG. 9 is a perspective view of the bottom lid of the carton after sealing; FIG. 10 is a partial side view of the bottom lid of the carton immediately before sealing; The figure is an exploded perspective view of the sealing horn after sealing during the carton removal process, the bottom-sealed carton, and the multi-sided mandrel pad; Figure 12 shows the sealing horn sandwiched between the sealing horn and the mandrel pad A cross-sectional view of the apparatus of FIG. 13 with respect to line 41-41 of FIG. 11 showing the forcibly engaged position of the folded carton bottom lid; FIG. Perspective view of the outer surface of the sealing horn and bottom lid: 1st
Figure 4 is a perspective view showing the broken part of the inner surface of the mandrel pad and carton bottom lid after the ultrasonic sealing operation; Figure 15 is a perspective view showing the inner surface of the carton bottom lid after the ultrasonic sealing operation. and FIG. 16 is a plan view of the outer surface of the bottom lid of the carton after the ultrasonic sealing operation.

2,20...carton bottom cover new) cleaning device, 4
...Base, 6...Support part, 8, 24
......Supporting mandrel, 10, 40...Mandrel pad with multiple faces, 12...(Folding plow), 14,22...Sealing horn ,
16, 27...Drive device, 28...Ultrasonic oscillator, 30...Sealing horn surface, 32
...Convex portion, 34...Concave portion, 44...
... Air passage, 47, 49 ... Air groove, 10
0...Carton material, 102,104...
Cut line, 108... Side seam tab, 110,
112... Triangular panel, 114, 116.
...Folding panel, 118, 120...
Triangular folding panel, 122, 124...Main panel, 125...Folding flap, 126.
...Polymerization flap, 200...Bottom lid part.

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Claims (1)

[Claims] 1. A method of ultrasonically sealing a pre-creased container double-coated with thermoplastic, such as a cardboard container double-coated with polyethylene, comprising: The material of the container is placed over a mandrel pad having an outer circumferential shape that approximately matches the shape of the inner wall of the container and is slid, thereby positioning the container and at the same time adjusting the shape of the main body of the container along the mandrel pad. folding the container closure to its final closed position and folding the container closure so that the container is slightly folded along a major fold line; pushing the thickened portion of the closure into a plurality of flat recesses in the mandrel pad so that it is substantially flush with the outer surface of the closure; vibrating a sealing horn provided in the ultrasonic range; pressing a folded closure between the mandrel pad and the ultrasonically vibrating protrusion of the sealing horn, thereby causing a sealing action; softening the double thermoplastic coating of the container material over the specific contact area formed by the protrusion of the horn, while simultaneously pressing the softened sides of the abutting layers of the folded container closure into contact with the tabs and panels; ceasing the ultrasonic vibrations of the sealing horn; and collapsing the softened thermoplastic coatings until they are in their hardened state. holding the folded container closure under pressure with a portion of the folded container closure within the plurality of recesses of the mandrel pad; A method for sealing a container, including the steps of: removing it from a container; 2 Bottom closure for sealing the bottom of a foldable cardboard container double coated with thermoplastic material In a sealing device used in a folding machine, the sealing device is for sealing the container and has a protrusion and a recess. and a body portion, the sealing member having a main body portion and a surface having a main body portion, and transmits ultrasonic vibrations to the bottom closing portion at the contact portion when the protruding portion is in contact with the bottom closing portion to form an ultrasonic seal of the contact portion. a working horn; a mandrel pad sandwiching a bottom closing portion between the sealing horn; and a device for driving the sealing horn and the mandrel pad in a direction in which they are pressed together; Mandrel pads are at least 2
contact of the folded bottom closure with the sealing horn and the mandrel pad; 1. A container sealing device, characterized in that it is shaped to accommodate an increased thickness corresponding to a folded panel of the bottom closure so that a substantially uniform force is applied to the bottom closure. 3. The apparatus of claim 2, wherein the faces of the mandrel pad are positioned in substantially parallel planes separated by an integral multiple of the thickness of the cardboard used in the container to be sealed. Container sealing device.